1. Field of the Invention
The present invention relates to a run-flat tire having improved run-flat durability without increasing rolling resistance and a spring constant.
2. Description of the Related Art
Conventionally, a run-flat tire that has a sidewall reinforcing layers each with a crescent cross-section shape in each sidewall portions is well known. Since the sidewall reinforcing layer can support a tire load in place of the internal air, the run-flat tire enables the vehicle to continue to be driven at a certain high speeds for limited certain distances when punctured.
The conventional run-flat tire with sidewall reinforcing layers, however, is liable to deteriorate ride comfort due to increased spring constant. Additionally, since the run-flat tire is liable to have a large weight, the tire has a problem that rolling resistance is larger.